Builder&#39;s tower



Ocf. 28, 1 o. L. 'BERBY BUILDER'S TOWER Filed Aug. 4, 1940 E 3Sheets-Sheet 2 Oct. 28, 1941.

O. L. BERBY BUILDER S- TOWER Filed Aug. 4, 1940 3 Sheets-Sheet 3Patented Oct. 28, 1941 UNITED STATES PATENT OFFICE .BUILDERS TOWER OlaL.. Berby,,Duluth, Minn, assig-nor to Clyde Iron Works, Duluth, Minn acorporation of Maine Application August 4, 1940, Serial No. 351,340

15 Claims.

My invention relates to an improvement in a bui-lders tower wherein itis desired to provide a simple and inexpensive tower which may be usedbycontractors and the like to lift material usedin the erection of abuilding.

Various types of towers to accomplish the same purpose have previouslybeen constructed.

It is usual practice to erect' an elevator frame of the desired heightand to place in this vertical frame an elevator or lifton which materialmay be carried to the properlelevation. 'Such a tower must, however, beerected on every construction job and cannot bereadily moved.

In order to provide a portable tower attempts havebeen made to provideconstructions in which the tower is mounted upon a movable basesupporting the hoisting apparatus. Most of these previous constructionshave been of two general types.

Certain of these towers have been providedwith a'cantilever platformmounted entirely to one side of the tower so that-wheelb-arrows,concrete-carriages and the like, may be wheeled directly onto theplatform from one side thereof and removed from the other-side of theplatform when elevated. This construction, however, necessitates anextremely rigidtower to support theeccentric loading. In order tosimplify' the construction and provide 'a more inexpensive tower,the'base has been provided with a pair of transversely aligned guidesbetween which a vertically slidable lift carriage is secured. With thistype of construction, however, it'has been necessary toposition thesupporting base at right angles to the building wall and it has beennecessary to move the wheelbarrowsor cement carriages onto the base toturn them at right angles'and to force'them onto the lift. This lessexpensive construction is obviously disadvantageous as'the base must beturned at right angles before it can be moved .along the wall andbecause of the'awkward arrangement for loading the lift.

*It is the purpose of the present invention to provide an extremelyinexpensive lift which may be provided with a-longitudinal frame. andwhich is provided with a'carriage which may be loaded directly from oneside of the lift and unloaded from the other side of the same. In thisconstruction 'a plane through the lift supporting guides extendsparallel to the wall of the build -ing being built and the lift iscentered between these guides. Wheelbarrows or concrete carriages may beloaded directly onto the lift by moving the same inwardly at rightangles to the building wall and in elevatedpOsi-tion may be withdrawnfrom the lift. Thus my novel form 'of construction-has the advantages ofboth of the former types of construction without the inherentdisadvantages previously encountered.

It is a feature of my invention 'to provide a builders tower embodying apair of spaced lift guides which are mounted on a line parallel to thelongitudinal axis of the supporting base. This construction provides thedirect loading advantage previously related. This construction alsopermits quick erection and lowering of the tower through the use of thehoisting apparatus mounted upon the tower base.

.ing apparatus balances the weight of the tower projected forwardly fromthe base, and in this lowered position the hoist may be moved from placeto, place with perfect balance. Such lowering of the tower isadvantageous where guy wires or overhead wires or cables of any sortprevent the movement of the tower in erected condition.

It isa further feature of my invention to have the vertical guidesspaced an equal distance apart throughout their height and to pivot 'across -member betweenthe upper endsof these guides on transverse pivotsparallel to the pivots connecting the vertical guides'to the base.- Thusin erection or lowering of the tower the guides together with the topcross member or head and -'the base form a .parallellogram whichmaintains all of the parts in proper relationship through'the raisingand lowering movement.

It is an object of my inventionto formthe vertical guides for the liftof tubular'members and to suspend the weight centrally between thesemembers. The tubular supports are capable of withstanding the weightupon'the lift and my tower can be built to a considerable height withoutunduly straining these supporting members. Not onlydoesthe round shapeofthe supports actto'better support the weight upon the lift; butalsothesupports provide efiicient guides for the lift and properly support thesame without undue friction.

It is a further feature of my invention that my lift may be easily andquickly removed from its position between the vertical guides and thatwhen in position between the guides acts to assist in preventingcollapse of the tower. The vertical guides forming the tower arepermitted to move in only one direction, that direction being in avertical plane through or parallel to the longitudinal axis of the base.When the lift and platform are assembled between the guides they assistin holding the guides parallel and in properly spaced relation, thusactually assisting to prevent the collapse of the tower.

A further feature of my invention relates to the simple manner ofsupporting the tower in vertical position. The vertical guides areequipped With guy wires which are pivotally secured at points spacedlater lly from the guides and on the pivotal axis of the towersupporting pivots. These guy wires therefore do not need to bedisconnected before the tower is lowered and act to support the towerfrom lateral movement in both erected and lowered positions. The guidesare further supported by brace means connected to the base which areconnected to the guides in raised position. One of these brace meansalso forms a raising cable guide by means -of whichthe tower may bepivoted upwardly by the hoisting mechanism.

It is a feature of my invention that the base of the lift which isnormally formed of heavy imaterial is permitted to drop below the levelof the pivotssupporting the vertical guides. Thus when the lift isdisassembled prior to lowering the top portion of the tower the lift maybe removed from the base, permitting the heavy base to remain in itsnormal position to facilitate the dismantling operation. The base isalso provided with a notch therein into which one of theguides extendsin lowered position to prevent transverse movement of the lift floor orbase upon the base of the tower during moving operations.

These and other objects and novel features of my invention will be moreclearly and fully set forth in the following specification and claims.

' In the drawings forming a part of my specification':

Figure l is a perspective view of my tower in erected position.

Figure 2 is a side elevation View of my tower in partially loweredposition, illustrating the tower in: fully lowered position in dottedoutline.

Figure 3 is a sectional view on a transverse plane through the tower,illustrating the base of the tower in plan view.

3 Figure 4 is a perspective view of one of the members forming the lift.

Figure 5 is a perspective view of the top cross members connecting theside members of the lift.

Figure 6 is a side elevation View of the top cross member of the lift,showing the construction thereof.

tower is erected and when it is partially erected.

Figure 11 is a section through the lower pivot of one of the verticalguides.

Figure 12 is a detail of the safety gate end.

Figure 13 is a detail of the mast splice.

Figure 14 is a section on the line I4I4 of Figure 13.

The builders tower A includes a base In, the formation of which is bestillustrated in Figures 1 and 3 of the drawings. The base I0 includes apair of longitudinally extending beams II having rounded ends to permitthe tower to be moved longitudinally over the surface of the ground. Afront cross member I3 extends between the runners II and is welded orotherwise affixed thereto. A parallel cross member I4 also connects therunners I I at a point spaced from the cross member I3. Two parallelspaced I-beams I5 and I6 extend between the runners II near the rearends thereof to support the hoisting unit indicated in general by thenumeral IT. A platform I9 is mounted between the I-beams I5 and I6adjacent the hoisting unit I! on which the operator of the hoist maystand. A pair of diagonally extending braces 20 are provided between theI-beam I6 and the center of the cross member I4 to hold'these elementsin proper relationship and to further reinforce the base.

, A p'air'of tubular standards 2I and 22 are pivoted by transversepivots 23 between ears such as 24 extending upwardly from the crossmembers I3 and I4. The pivots 23 extend through the spaced ears 24 andthrough a plate 25 welded to the interior of the guides 2I and 22 andprojecting beyond the ends thereof. The specific detail ofthisconstruction is best illustrated in Figure 11 of the-drawings.

The-tubular standards 2I and 22 are connected at their upper extremityby a cross support or head 26. This head 26 is best illustrated inFigures' '6, 7 and 8 of the drawings. In the form illustrated the headincludes a pair of spaced channels 21 held in spaced relation by shortlinks of angle iron 29, 30 and 3!. Pivots 32 and 33-extend through thechannels 21 and through the upper extremities of the tubular guides 2|and 22 to pivotally secure the head to the guides.

An inverted U-shaped cable guide 33 having parallel sides 34 and flangedlower ends 35 is secured between the channels 21 at one end thereofadjacent the angle 29. A pulley 3'6 is pivoted on a transverse pivot 31between the parallel sides 34. The cable extends over the pulley 35 andis guided thereby.

' A pair of vertically extending plates 39 extend upwardly from thechannels 21 between the angles 30 and Lil and support the pivot 40 for apulley 4|. The pulley 4| receives the cable 42 from the pulley 36 andthis pulley M is arranged 'Side guides 46 best illustrated in Figure 4of the drawings are attached to these end plates 45.

' The side guides for the ends of the platform 43 include a verticalchannel 41 formed of a pair of angle irons having an attaching plate 49welded to the bottom end thereof. Bolts 50 extend through the end plates45 and through the attaching plate 49 to hold the channels 41 to theplatform' 43. Braces are welded to the base of the channel at apointspaced-from the bottom thereof and bolts 52 extend through the lowerextremities of these'braces-and through the end plates --to hold thechannelsl'l-"in vertical alignment. Transversel'y extending braces 53extend between the braces 5| connecting these braces at spaced 1intervals with the channel" 41. *The transverse braces 53 are spacedapart properly to forma ladder up which an operator may climb. 'Verticalend posts-58 support the ends of the transverse braces-53.

A pair of transversely extending arms-54 are secured in'spaced relationextending in right angles from the channel 41. A brace 55 is con-:nected atone end to thechannel 41 and atthe other end between theparallel arms-'54 to sup port the aarms' 54. A pair of openings 56 areprovided in spaced relation through the arms 54 and-the spacing of theopenings 56'matches the spacing'of pairs of holes 51 or 59 inthechannels" 60. The cross member at the top of the lift is formedby thetwo channels 50 secured in opposed relationship and these channels maybe readily lifted by the operator and bolts extended through theopenings 51 and 59 and through the openings "56 on the transverselyextending arms 54 of the two side guides 45'.

A vertical support is provided adjacent the-upright-2| by a pairof-spacedangle irons"6|. A plate 62, best illustrated in Figure 3 of thedrawings is secured to the upper surface of the braces 29 of the base bymeans of' bolts '63 or the like, and the angle members 6 extendvertically from this plate 62. A'pair of brackets 54 are provided ontheangle membersfil near the top end thereof and-these brackets Mare pinconnected to a pair of braces whichare bolted-to the lower extremity ofthe braces 2|] at 66 in the manner illustrated in Figures l and '3 ofthe drawings.-

As shown in Figures 1, 2 and 3 of the drawings, the ears 61 extendupwardly from the runners or longitudinal beams to form pivotal supportsfor a pair of braces 69. These braces'69 are pivoted at one end at lflto the ears 6'! and are connected'at theother end II. 'In loweredposition of the tower the braces 59 extend'forwardly "from the runnersand may be used as a drawbar if it is so desired In erected position ofthetower "the'ends H of the braces 69 are connected to a bracket plate.12 on the guides 22 by means of a -members" being connected together-atthe top. 'of'the tripod and all of the'membersbeing secured to the base.When :the braces 59 are connected to the upright 22, a second tripod isformed, themembers being connectedtogether at the top of the tripod :andthe lower endsof all of the members being securely fastened to the baseIll. p 7

On the upper extremity of the upright EM between the angles forming this.upright,'I provide apulley mounted upon a removable pin ,or bolt 19.Extending rearwardly' from the upper ends of the angles 6|,I provideplates which terminate in converging guides 8! for guidingthe .cable .42into engagemenfwitnthe pulley '11.

This construction is for 'a purpose which will 1 later be described indetail in connection with cal'guide 22 from sidesway or movement. Guy

"'83 and the plates on the vertical guide "2| t support this guidefromtransverse movement. These guy ropes and cables '86 and 8l may remainconnected even during the raising and lowering of the tower; as thelower ends of the cables are pivoted at' 89 and99. respectively,- inalignmentwith the pivots 2301. the respective vertical guides 22 and 2|.i

The hoistingunit maybe providedwitha single drum 9| with suitablecontrolstherefor,

and maybe driven by the engine- 92. The hoisting unit also preferablyincludes a winch head 93 by means of which the towerrnay be movedalongthe ground. The line or cable-42 is used both tooperate the liftand to raise' and lower the tower. Whenthe tower is in the folded formillustrated in dotted outline inFigure 2 of the drawings, 'a channel 94secured to the top cross member channels?! rests upon the surface of theground and sup-ports the top cross member or head in slightly raisedposition. The construction of the channel 94 is illustrated inFigures-l, 2, and 6 of the drawings, and' i's shown connected at itsupper'e'nd to the channels 2'! and also connectedthereto by braces"95which extend diagonally between the sides of the 'channels 94 andthechannels'Z'l. Theb'races 95 are spacedsufficiently and the channel94' is ofsp-ropor size to permit the vertical guide 22 to move freelywithin the same. This channel 94 limits the downward pivoting or themasts or uprights 2| and 22, preventing distortion-or strain. Thischannel 94 thus provides protection for the-masts and also for thepivots 23connecting-themasts to the base. v,

When the tower is in the lOWered position shown in dotted outline inFigure 2, the cable 42 extends from the cable drum 9| over the to'pofthe pulley 11} between the i-shaped bracket 33 and the pulley 35 on thehead 26,;over the pulley 4| and is dead-ended to a plate 9l on theoutersurface ,of the vertical guide 2|. -In order to becomes more and moreerect, the cable :42 pulls away from the pulley Tl, as it, of course,then assumes a straight line pull between thepulley 36 and the drum' 9The erection continues until the plate 14 is pulled between the fixedplates 15 on the upright standard 6 whereupon thetower is held in thisposition by means of the: cable used in-conjunction'theretween the crossmembers IS and l4. With the upright guides 2| and 22 held in positionbythe hoisting unit |"|,-theside guides (raresecured to the platform 43.The. side: guides =46 are of such a'weight that theymay ordinarily behimdled by a single-man or byt'wo men workingin conjunction. The bolts50 secure the. channel 41 in upright position, and the braces5| aresecured by the bolts 52 to the end plates 45 on the platform 43. Whenthe eight necessary bolts have been secured, the channels 60 are liftedinto place.

The channels 60 are spaced from the platform 43 such a distance that aworkman can lift these channels into place while standing upon theplatform 43. Bolts are then inserted through the holes 51 and 59 of thechannel 60 and through the corresponding holes 56 in the arms 54 tosecure the two channels in spaced relation between the channels 41 inthe manner illustrated in Figures 1 and 3 of the drawings.

When the cross member formed by the channels 60 is in place, a workmancan climb up upon:

this cross member and insert a pin connection between the plate I5 andthe plate I4 on the vertical support 2I. This pin I6 holds the uprightguide 2I securely to the tripod formed by the vertical members BI andthe braces 65. The

braces 69 may then be pivoted up into engagement with the plate I2 and apin "I3 may be inserted between the upper extremity of the braces 69 andthe plate I2 to hold the upright 22 erect.

The cable 42 may then be released by the hoist-.

ing unit II and the pin 99 may be removed which holds the cable 42 tothe bracket plate 91'. The end of the cable 42 is then inserted betweenthe channels 60 and a pin I may be extended through the loop on the endof the cable 42 to secure the cable to the channel 60 and accordingly tothe lift.

While the workman is standing upon the channel 60, the pin I9 holdingthe pulley II in place is removed and the cable 42 is placed betweenthis pulley TI and the vertical support 2i. Thus the cable is directedbeneath the pulley I! up over the pulley 35 and over the pulley 4|before being connected to the lift.

When the tower has been fully erected and the lift assembled, the liftmay be raised and lowered by means of the hoisting unit II. As will beapparent from the drawings, the base I0 extends with its longitudinalaxis parallel to the wall of the building being constructed andwheelbarrows or concrete carriages may be wheeled onto this platform. Bywheeling the wheelbarrows or the like directly toward the building wall,they may be rolled onto the platform 43.

When the wheelbarrows are in place, the hoist may be lifted to theproper elevation, and the wheelbarrows may then be removed from theopposite side of the hoist which is adjacent the building wall.Obviously, there is no difficulty in moving the wheelbarrows and thelike onto or off the lift, and the lift is centered between the verticalguides, making the construction extremely strong.

Under some circumstances, it is desirable to provide a guide railingwhich may be automati cally engaged along the outer edge of the elevator cage to protect the workmen unloading the cage in elevatedposition. It is of course necessary to remove such a railing in loweredposition of the cage in order to permit loading of the cage from theside away from the building. In order to accomplish the desired result,I provide a pair of substantially U-shaped brackets IIII having flaredupper extremities I02 to support the railing indicated in general by thenumeral I03. The brackets IOI are secured to the vertical end posts 58connecting the cross braces 83 of the elevator cage side members 46.These U-shaped brackets IOI are designed to receive a pair of cross barsI05 forming a part of the railing I03 to support this railing inposition to close the outer edge of the elevator cage. Obviously thebrackets IOI may be secured at either end of the side guides 46 so thatthe railing I03 may be attached to either side of the elevator cage.

In order to automatically remove the protective railing I03 as theelevator cage moves toward its lowermost position, I provide a pair ofbraces I0'I secured to the outer surfaces of the vertical masts 2| and22. U-shaped brackets I09 having flared upper ends IIO are supported atthe outer extremities of these braces I01. As the elevator cage movesupwardly, the brackets IIII engage the cross'bars I05 inwardly of thebrackets I09, and lift the railing I03 out of engagement with thebrackets I09, the railing then being attached to the 'elevator cage toform a protective guard for the outer edge of the same. A slopingsurface formed by the cams I 08 acts 0 to center the railing with thebrackets I M. As the elevator cage lowers, however, the cross membersI05 again engage in the brackets I09, and these brackets prevent therailing I03 from lowering further with the cage, thus holding therailing suspended in air to permit free loading of the elevator cage. Asloping surface formed by the bent ends II4 of the lower bar I05 centersthe railing with the brackets I09.

The railing may be of any desired type and is illustrated with two crossbars I05 which are engagable in the brackets IOI and I 09 and a paralleltoeboard II I. The cross members I05 and the toeboard III are connectedby side frame members H2 and a central frame member H3.

The masts may be spliced in the manner best illustrated in Figures 13and 14 of the drawings. As shown in these figures, the lower section II5of each mast or support such as 2| or 22 is slotted at IIB adjacent itsupper end. Lugs III and H9 are welded to the section II5 on oppositesides of the slot H6, and bolts I20 extend through the lugs I I1 and II9 to clamp the portion of the pipe on opposite sides of the slot II6together.

A short length of pipe IZI is welded within the upper section I22 of themast, to project downwardly therefrom. This welding is accomplished bycutting holes I23 in the pipe I22, and welding through these holes. Theprojecting portion of the pipe I2I extends into the upper end of thelower section H5, and is clamped in place by the bolts I20.

When the lift is in lowered position the hoist may be readily movedalong the surface of the ground without pivoting the tower into foldedposition. I have found that my tower may be moved over ground which isquite rough without danger of tipping or tilting because of the lowcenter of gravity of my device when the lift is in lowered position. If,however, it is necessary to avoid guy wires or overhead obstructions,the lift may be easily taken apart and the tower may be folded down intothe dotted outline position of Figure 2 in an extremely short space oftime. Tests have shown that my builders tower may be completely erectedor lowered in ten to fifteen minutes time.

In accordance with the patent statutes, I have described the principlesof construction and operation of my builders tower; and while I haveendeavored to set forth the best embodiment thereof, I desire to have itunderstood that this is only illustrative of a means of carrying out my7 invention and that obvious changes may be made within the scope of thefollowing claimswithout departingv from the spirit of any invention.

-I claim: 3 r I I A builders tower comprising a base, apair of spacedguides extending. upwardly from said base, a cross member connecting theupper extremities of said guides, parallel pivots connecting said crossmember to, saidguides and connecting said guides to said base to formaparallelogram, an elevator. supported by said guides including aplatform which may be lowered below the level of said guides and belowthe level of said pivots connecting said guides to said base, andremovable engaging means on said platform. i

- of said vertical guide members, an elevator supportedbyand verticallyslidable with respect to ,said guides, parallel pivots connecting saidvertical guides to said base and to said cross member, and guy memberssecured to. said vertical guides-at a point spaced from theibottomthereof connected to said .base coaxially. with said pivots connectingsaid guides to-said base.

7., A builders tower comprising an elongated base, a pair. of.verticallyextending longitudinalfly spaced guide members extendingupwardly fromsaid base, a cross member connecting the ,upper extremitiesof said guides, parallel pivots connecting said cross member to .saidvertical 2. A builders tower comprising an elongated movably secured tosaid platform, a hoist on 7 said base near the other end thereof, andmeans connecting said hoist to said elevator platform. 3. A builderstower comprising an elongated base, a pair of vertical guides extendingupwardly in longitudinally spaced relation from said base, a crossmember connecting the upper extremities of said guides, paralleltransversely extending pivots connecting said cross member to saidguides and said guides to said base to form a parallelogram, a verticalsupport projecting upwardly from said base adjacent one of said verticalguides and detachably connected thereto, a hoisting mechanism on saidbase, a Vertically reciprocable elevator between said guides, and cablemeans connecting said elevator to said hoisting mechanism by means ofwhich said elevator may be raised and lowered.

4. .A builders tower comprising an elongated base, a pair of verticalguides extending upwardly in longitudinally spaced relation from saidbase, a cross member connecting the upper extremity of said verticalguides, parallel pivots connecting said cross member to said guides andconnecting said guides to said base, a vertical support extendingupwardly from said base adjacent one of said guides, a pulley on saidvertical support, pulley means on said cross member, a hoist on saidbase, and cable means extending over said pulley on said verticalsupport over said pulleys on said cross member and extending betweensaid guides, and a vertically movable elevator connected to said cablebetween said guides.

5. A builders tower comprising an elongated base, a pair of verticalguides extending upwardly in longitudinally spaced relationship fromsaid base, brace means connecting said base to said vertical guides at apoint spaced from the bottom thereof, a hoisting unit on said base, across member connecting the upper extremities of said guides, anelevator vertically slidably supported between said guides, and meansconnecting said hoist to said elevator to raise and lower the elevatorby said hoist.

6. A builders tower comprising an elongated base, a pair oflongitudinally spaced vertically extending guide members projectingupwardly from said base, transverse pivot means connecting said verticalguide members to said base, a cross member connecting the upperextremities guides and connecting said guidesfto said base to form aparallelogram, an elevator between said guides and movable to apositionbelow said pivotsconnectingsaid guides to said base, slides on saidplatform engageable with said vertical guides removably connected tosaid platform, an

, upwardly extending end plate on said platform having a .notch thereininto which one of said vertical guides may extend when said guides are,pivoted downwardly with respect to said base.

8. A builders tower comprising a base, a pair of 'verticallyextendingguides secured in spaced .relation upon said base, brace meansconnecting saidvertical guides to said base, an elevator ver- 'ticallyslidable between 'jsaidguides, said elevator including a platform,removable sides secured thereto engageable with said vertical guides andcross members connecting said removable sides to hold said sides inengagement with said guides, a hoisting mechanism on said base, andmeans connecting said hoisting mechanism with said elevator to raise andlower said elevator by said hoisting mechanism.

9. A builders tower comprising an elongated base, a pair of standardspivotally secured in spaced relation to said base, a cross memberconnecting the upper extremities of said standards, parallel pivot meansconnecting said cross member to said standards ad connecting saidstandards to said base to form a parallelogram, a cable guide supportprojecting upwardly from said base adjacent one of said standards, meansremovably connecting said one standard to said cable guide support, ahoisting unit and an elevator between said standards and flexible cablemeans connected to said hoisting unit guided by said cable guide meansand connected to said elevator to raise and lower said elevator by meansof said hoisting unit.

10. A builders tower comprising an elongated base, a pair of standardsextending vertically in spaced relation from said base, a verticallymovable elevator supported between said standards, said elevatorincluding a platform, sides secured to said platform engageable withsaid standards, means connecting said sides to hold said sides inengagement with said standards, cross brace means on said sides forminga ladder con-v struction, a hoisting unit on said base, and meansconnecting said hoisting unit with said elevator to raise and lower saidelevator with said hoisting unit.

11. A builders tower comprising a base, a pair of standards projectingupwardly from said base, a cross member connecting the upper extremitiesof said standards, parallel pivots connecting said cross member to saidstandards, and connecting ,said standards to said base to form aparallelovator to raise and lower said elevator by said hoisting unit,and a right-angular brace secured to said cross member to limit pivotalmovement between said cross member and said vertical standards in onedirection.

12. A builders tower comprising an elongated base, a pair oflongitudinally spaced vertical standards projecting upwardly from saidbase, a cross member connecting the upper extremities of said standards,parallel pivots connecting said cross member to said standards andconnecting said standards to said base, an elevator removably positionedbetween said standards, a hoisting unit on said base, an upwardlyprojecting cable guide secured to said base, a pulley supported by saidupwardly projecting support in alignment with said vertical standards,and brace means removably supporting said standards in verticallyextending position.

13. A builders tower comprising a vertically extending mast, a base towhich said mast is secured, an elevator cage vertically movable on saidmast, a removable railing on one edge of said cage, substantiallyU-shaped brackets supporting said railing in place on said cage, and apair of brackets extending in the path of said railing to engage saidrailing as said cage lowers to remove said railing from operativeposition with respect to said cage.

14.-A builders tower comprising an elongated base frame, a pair ofspaced vertical guides pivotally connected to said frame, said guidesbeing positioned ona vertical plane through the base and through orsubstantially parallel to the longitudinal axis of said base frame, ahead pivotally connecting the upper extremities of said guides, saidguides being pivotally movable in said vertical plane, an elevator cagesupported by said guides, a hoisting unit secured to said base, andflexibleconnecting means connecting said hoisting unit to said elevatorcage, whereby said elevator cage may be vertically reciprocated by saidhoisting unit.

15. A builders tower comprising an elongated base frame; a hoistingmechanism thereupon, a pair of vertical guides secured in longitudinallyspaced relation on said base frame,,transversely extending pivotsconnecting said vertical guides to said'base frame whereby said guidesmay be pivoted I toward horizontal ,position maintaining parallelrelationship, an elevator cage between said guides and engaging opposedinner surfaces thereof, and flexible means connecting said elevator cagebetween said vertical guides.

OLA L. BERBY.

